Universal spark-plug tester



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G. G. NAUGLE UNIVERSAL SPARK PLUG TESTER Filed May 4, 1923 gwn/rdm HaaghPatented Oct. 21, 1924.

UNITED STATES PATENT OFFICE.

GIRARDUS G. NAUGLE, OF YORK, PENNSYLVANIA, ASSIGNOR T0 CARLTON L. HOFF,

0F YORK, PENNSYLVANIA.

UNIVERSAL SPARK-PLUG TEs'rEB.

Application filed May 4, 1928. Serial No. 636,601.

To all 'whom t may concern:

Be :itv known that I, GTRARDUS G. NAUGLE, a citizen of the UnitedStates, residing at York, in the county of York and State ofPennsylvania,l have invented certain new and .useful Improvements inUniversal Spark-Plug Testers; and I do hereby declare the following tobe a full, clear, and exact description of the same, reference being hadto the accompanying drawings, forming part of this specification.

This invention relates to a spark plug tester and has for its obj ectthe provision of a tester which will permit the testing of a spark plugirrespective of the variations and threads on the plug.

' A further object of the invention is to provide a simple and reliablespark plug tester.

There are in common use in this country a great number of makes of sparkplugs and unfortunately the threads on the spark plugs have not yet beenstandardized, there being three largely used sizes of threads and thisrequires three different spark plug testers of the usual type one foreach of the three styles of plugs. In the structure shown in thedrawings a single housing is provided and a rotatable disk is mounted onthe housing so as to bring any one of three'tapped openings intoregistry with the pressure chamber so that any spark plug may be testedwith. ease.

In the drawings, y

Figure 1 is a front elevation of a spark plug tester made in accordancewith my invention.

Fig. 2 is a central vertical section.

The main casting or housing consists of a substantially circular plate10 having an integral base 12 formed therewith by means of a stiffeningrib 14. A cylindrical pressure chamber 15 extends forwardly from theplate lO and like the rib and base is an integral part of the housingor`casting. 'Ihe front side of the pressure chamber 14 is closed by adisk of glass 17 held in place between two steel washers 18 by means ofa hollow threaded plug 19 having a square end 20 for convenientinsertion and removal of the plug. The rear face of the casting orhousing is machined and receives a similarly machined face of arotatable holder 22 pivoted to the housing by means of a bolt 25. Theholder 22 is provided with three equally spaced openings 26, 27 and 28each tapped Aopenin to receive a spark plug of one of the three standardtypes and by rotation of the spark plug holder 22 and one of the threeholes may be brought into registry with the axis of the pressurechamber. I find it convenient to engrave a mark on the periphery of thedisk-like holder 22 in line with each of the three openings and to thenengrave a similar mark on the housing in or to facilitate the exactregistry of the desired opening with the pressure chamber. When the 26,27 or 28 with its spark plug 29 in p ace and ready to be tested isbrought into registry with the pressure chamber the bolt 25 is tightenedat which time the presstandard gage 31 in the line between the testerand a pump not shown.

The spark plug 29 is connected through f sure chamber is closed exceptfor its com- -mun1cation through the pipe 30 with a a battery 32 withthe metal of the housing providing the customary high tension sparkbetween the electrodes of the plug.. Fluid under pressure is conveyed tothe pressure chamber by means of pipe 36 and if desired the pressure inthe chamber may be brought to the highest pressure shown on the dial ofthe gage 31 and the valve 37 closed when such pressure is reached. Thesupply of current to the spark plug is now closed by means of switch 39and the air allowed to leak slowly from the chamber by a slight openingof the valve 37 so by watchlng through the peep hole in the stud 2O andat the same time by observing the dial of the y gage-37 it is possibleto determine the exact said chamber, characterized by the spark.

plug holding means being rotatable and having a plurality of spark plugholding openings therein.

2. A spark plug tester of the type havin a pressure chamber, a gageconnected wit said chamber, means for conveying fluid under pressure tosaid chamber, and means for holding a spark plug in registry with saidchamber, characterlzed by the spark Aplug holding means being rotatableand having a plurality of spark plug holding openings therein, saidopenings being of dii'- ferent diameters.

3. A spark plug tester of the type having a pressure chamber, a gageconnected with said chamber, means for conveying fluid under pressure tosaid chamber, and means for 'holding a spa-rk plug in registry with saidchamber, characterized by the spark plug holding means being rotatableand havn ing a plurality of spark plug holding openings therein, thespark plug holding means comprising a disk provided with a plurality ofopenings adapted to be successively brought into registry with saidchamber, said disk being pivoted to the chamber housing to one sideofthe axis of said chamber, said disk and said housing having machinedcooperating surfaces.

4. In a spark plug tester, a support havinga cylindrical chamber thereinof substantially the same diameter as a spark plug, a transparentclosure for said chamber, a hollow plug for holding said closure inplace, means for holding a spark plug coaxial with said chamber and saidhollow plug, and means for conveying fluid under pressure to saidChamber, said holding means being rotatable about an axis parallel tothe axis of said chamber and hollow plug.

5. The device of claim 4- in which the spark plug holder has a pluralityof threaded openings therein of different diameters.

GIRARDUS G. NAUGLE. Witness:

GEORGE S. DELLINGER.

